Collapsible prosthetic heart valves

ABSTRACT

Prosthetic heart valves, which are collapsible to a relatively small circumferential size for less invasive delivery into a patient and which then re-expand to operating size at an implant site in the patient, include a collapsible/expandable stent-like supporting structure and various components of flexible, sheet-like material that are attached to the supporting structure. For example, these sheet-like other components may include prosthetic valve leaflets, layers of buffering material, cuff material, etc. Improved structures and techniques are provided for securing such other components to the stent-like supporting structure of the valve.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 14/334,059, filed Jul. 17, 2014, which is a continuation ofU.S. patent application Ser. No. 13/848,466, filed Mar. 21, 2013, nowU.S. Pat. No. 8,845,721, which is a continuation of Ser. No. 12/733,759,filed Mar. 18, 2010, now U.S. Pat. No. 8,425,593, which is a nationalphase entry under 35 U.S.C. §371 of International Application No.PCT/US2008/011153 filed Sep. 26, 2008, published in English, whichclaims the benefit of U.S. Provisional Application No. 60/995,648 filedSep. 26, 2007, all of which are hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION

Current collapsible prosthetic heart valve designs are for use withinpatients who may need a valve replacement (e.g., an aortic valvereplacement), but who are not treated adequately by other means. Acollapsible prosthetic heart valve is designed to be delivered into thepatient in a collapsed condition via tube-like delivery apparatus. Inthe collapsed condition the valve has a reduced annular, radial, orcircumferential size. Delivery of the valve into the patient can be lessinvasive than traditional open-chest/open-heart surgery. When the valvereaches the intended implant site in the patient, the valve re-expandsor is expanded (e.g., balloon expanded) to operating size. Thecollapsing and re-expansion of the valve are preferably elastic, but mayalternatively be plastic, the result of shape-memory properties ofcertain components of the valve, or various combinations of elastic,plastic, and/or shape-memory. Again, plastic expansion may be as aresult of inflation of a balloon that is temporarily disposed inside thevalve. Known designs of this general kind can be implantedpercutaneously, trans-apically, or surgically, with or without resectedand/or debrided native heart valve leaflets.

SUMMARY OF THE INVENTION

The prosthetic heart valves disclosed herein incorporate a collapsiblevalve (which may or may not include independently flexing commissureposts) and unique ways in which to assemble the leaflets and ancillarycomponents.

In accordance with certain possible aspects of the invention, aprosthetic heart valve may include an annular, annularly collapsible andre-expandable supporting structure, and a sheet-like, flexible, leafletmember mounted inside the supporting structure so that a free edgeportion of the leaflet forms a flexible chord across an interior of thesupporting structure. Material of the leaflet may extend beyond an endof the chord and form a flap that is folded to lie, at least in part, ina cylindrical surface defined by one of the inner and outer surfaces ofthe supporting structure.

The above-mentioned flap may be secured to the supporting structure. Forexample, the flap may be sutured to the supporting structure to securethe flap to the supporting structure. As a more particular example, theflap may lie, at least in part, in the cylindrical surface defined bythe inner surface of the supporting structure. Alternatively, the flapmay pass through the supporting structure to lie, at least in part, inthe cylindrical surface defined by the outer surface of the supportingstructure.

The leaflet may have a secured line portion which is spaced from thefree edge portion across an intervening belly portion of the leaflet.The secured line portion may be secured to the supporting structure, andadditional material of the leaflet beyond the secured line portion awayfrom the belly portion may form a second flap that is folded to lie, atleast in part, in a cylindrical surface defined by one of the inner andouter surfaces of the supporting structure.

The above-mentioned second flap may be folded toward the free edgeportion of the leaflet and secured to the supporting structure insidethe supporting structure. Alternatively, the second flap may be foldedaway the free edge portion and secured to the supporting structureinside the supporting structure. Especially in the latter case, thesecond flap may continue beyond an axial end of the supporting structureand may be additionally folded over that axial end and back outside ofthe supporting structure for additional securement to the outside of thesupporting structure.

A prosthetic heart valve in accordance with the invention mayadditionally include sheet-like, flexible, buffer material between thesupporting structure and the leaflet. Buffer material can alternativelybe provided so that it only outlines (covers) certain members of thesupporting structure, instead of forming a more extensive continuoussheet that covers not only members of the supporting structure but alsootherwise open cells of that structure. For example, such outlining orless extensive buffer material can be a dip-coated or sprayed-onpolymer.

The supporting structure of a prosthetic heart valve in accordance withthe invention may include a plurality of annularly spaced commissureposts, each of which may be cantilevered from other structure of thesupporting structure. The above-mentioned flap that extends beyond anend of the above-mentioned free edge chord of the leaflet may be securedto an associated one of the commissure posts. For example, thissecurement may be by suture material that passes through the flap andapertures through the associated commissure post. The flap may be foldedaround the associated commissure post. The associated commissure postmay be bifurcated into two spaced apart members. The flap may passthrough the commissure post between those two members.

In accordance with another possible aspect of the invention, thesupporting structure may include a plurality of annular, annularlycollapsible and re-expandable substructures that are spaced from oneanother along an axis about which the supporting structure is annular.The supporting structure may further include a plurality of linkingmembers that are substantially parallel to the above-mentioned axis andthat interconnect the substructures without the linking membersdeforming when the substructures annularly collapse and re-expand.

In accordance with yet another possible aspect of the invention, aleaflet structure for a prosthetic heart valve may include a sheet offlexible leaflet material having a central opening with three sides,each of the sides being shaped to form the free edge of a respective oneof three operating leaflet portions of the leaflet structure. The sheetmay additionally have three secured line portions, each of which isradially outward from a respective, associated one of the free edges,and each of which is arcuate so that it is radially farther from amidpoint of the associated free edge than from endpoints of theassociated free edge.

The above-mentioned sheet may define three leaflet-linking areas, eachof which extends from a junction of a respective pair of the free edgesto a junction of the secured line portions that are radially outwardfrom the free edges in that pair.

For use of the above-mentioned sheet, a prosthetic heart valve inaccordance with the invention may include an annular, annularlycollapsible and re-expandable supporting structure. The above-mentionedsheet may then be disposed in the supporting structure with the securedline portions and the leaflet-linking areas secured to the supportingstructure so that the free edges can come together in the interior ofthe supporting structure. The supporting structure may include threeannularly spaced commissure posts, each of which may or may not becantilevered from other structure of the supporting structure. Each ofthe leaflet-linking areas may be secured to a respective one of thecommissure posts. At least one of the leaflet-linking areas may passoutside the supporting structure at the commissure post to which thatleaflet-linking area is secured. At least one of the commissure postsmay be bifurcated into two spaced apart members, and the leaflet-linkingarea that is secured to that commissure post may pass between the twomembers of that commissure post.

The above-mentioned sheet may continue radially outwardly beyond atleast a portion of at least one of the secured line portions to form aflap. In use of the sheet in a prosthetic heart valve that includes asupporting structure as mentioned above, such a flap may be secured tothe supporting structure. For example, the flap may be secured insidethe supporting structure. Alternatively, the flap may be secured outsidethe supporting structure.

As another possibility, in use of the above-mentioned sheet in aprosthetic heart valve that includes a supporting structure (as alsomentioned above), the valve may also include sheet-like, flexible,buffer material between the supporting structure and the leafletmaterial.

In accordance with other possible aspects of the invention, a prostheticheart valve may include an annular, annularly collapsible andre-expandable supporting structure, which in turn includes a pluralityof members disposed in a zig-zag pattern that extends in a directionthat is annular of the supporting structure. At least two of the membersforming such a zig-zag pattern meet at an apex that points away from thesupporting structure parallel to an axis about which the supportingstructure is annular. The valve may further include a sheet of flexiblematerial secured to the supporting structure, and a plurality offlexible leaflets disposed inside the supporting structure and at leastpartly secured to the sheet. The sheet may be at least partly secured tothe supporting structure via a suture attachment at the apex. The apexmay be shaped to prevent the suture attachment from moving away from theapex in a direction opposite to a direction in which the apex points.

As a specific example, the above-mentioned apex may include an eyeletthrough which the suture attachment passes. As another example, the apexmay include an enlarged head on the end of a reduced neck that extendsin the direction that the apex points, and a suture attachment for theabove-mentioned sheet may be wound around the neck. As still anotherexample, the apex may comprise a notch that opens in the direction thatthe apex points, and the above-mentioned suture attachment may be woundaround the inside of the apex and the inside of the notch. Theabove-mentioned notch may be narrowed near its entrance to form an openeyelet. Such an open eyelet may be too small for passage of a sutureneedle, but the entrance may be large enough for suture material to slipthrough.

Further features of the invention, its nature and various advantages,will be more apparent from the accompanying drawings and the followingdetailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a simplified elevational view of an illustrative embodimentof a component that can be used in prosthetic heart valves in accordancewith the invention.

FIG. 1B is an isometric or perspective view of what is shown in FIG. 1A.

FIG. 2A is a simplified elevational view of an alternative embodiment ofwhat is shown in FIG. 1A. FIG. 2A shows only the foreground portion ofthe depicted component.

FIG. 2B is similar to FIG. 2A, but from a different angle and with partsof the background structure shown in addition to the foregroundstructure.

FIG. 3A is similar to FIG. 2A, but with illustrative additionalcomponents added.

FIG. 3B is similar to FIG. 3A, but with illustrative, still furthercomponents added.

FIG. 4A is a flat development of an illustrative embodiment of what isactually a cylindrical component, which can be used in prosthetic heartvalves in accordance with the invention.

FIG. 4B is an elevational view of the cylindrical component that isshown in flat-development form in FIG. 4A.

FIG. 5A is similar to FIG. 4A for another illustrative embodiment.

FIG. 5B is an enlargement of a portion of FIG. 5A.

FIG. 6 is an elevational view of an illustrative embodiment of anothercomponent that can be used in prosthetic heart valves in accordance withthe invention.

FIG. 7 is similar to FIG. 6 for another illustrative embodiment.

FIG. 8 is similar to FIG. 7 for still another illustrative embodiment.

FIG. 9 is similar to FIG. 8 for yet another illustrative embodiment.

FIG. 10 is an elevational view of an illustrative embodiment of stillanother component that can be used in prosthetic heart valves inaccordance with the invention.

FIG. 11 is a simplified perspective view of an illustrative embodimentof an assembly of several components in accordance with the invention.

FIG. 12A is a simplified, partial, top view of an illustrativeembodiment of an assembly of several components in accordance with theinvention.

FIG. 12B is similar to FIG. 12A for another illustrative embodiment.

FIG. 12C is similar to FIG. 12B for still another illustrativeembodiment.

FIGS. 13 and 14 are each generally similar to FIG. 11.

FIG. 15A is a simplified, partial, elevational view of an illustrativeembodiment of an assembly of several components in accordance with theinvention.

FIG. 15B is another view of the same general kind as FIG. 15A.

FIG. 16 is a bottom view of an illustrative embodiment of an assembly ofseveral components in accordance with the invention.

FIG. 17 is similar to FIG. 5B for another illustrative embodiment.

FIG. 18A is a simplified isometric or perspective view of anillustrative embodiment of an assembly of several components inaccordance with the invention.

FIG. 18B is a simplified, partial, elevational view of an illustrativeembodiment of several components in accordance with the invention.

FIG. 19 is similar to FIG. 10 for another illustrative embodiment.

FIG. 20A is a simplified, partial, top view of an illustrativeembodiment of an assembly of several components in accordance with theinvention.

FIG. 20B is a simplified sectional view of part of what is shown in FIG.20A.

FIG. 21 is similar to FIG. 19 for another illustrative embodiment.

FIG. 22 is similar to FIG. 18A for another illustrative embodiment.

FIG. 23A is similar to FIG. 12C for another illustrative embodiment.

FIG. 23B is similar to FIG. 23A for another illustrative embodiment.

FIG. 24A is similar to FIG. 5A for another illustrative embodiment.

FIG. 24B is similar to FIG. 5B for another illustrative embodiment.

FIGS. 25A and 25B are each similar to FIG. 21 for other illustrativeembodiments.

FIGS. 26A and 26B are each similar to FIG. 23B for other illustrativeembodiments.

FIG. 27 is similar to FIG. 22 for another illustrative embodiment.

FIG. 28 is similar to FIG. 24B for another illustrative embodiment.

FIGS. 29A and 29B are respectively similar to FIGS. 24A and 24B foranother illustrative embodiment.

FIG. 30 is similar to FIG. 1A for another illustrative embodiment.

FIG. 31 is similar to FIG. 29B for another illustrative embodiment.

FIG. 32 is similar to FIG. 8 for another illustrative embodiment.

FIGS. 33A and 33B are each similar to FIG. 25B for other illustrativeembodiments.

FIG. 34 is similar to FIG. 26B for another illustrative embodiment.

FIGS. 35A and 35B are each similar to FIG. 15B for another illustrativeembodiment.

FIG. 36 is similar to FIG. 21 for another illustrative embodiment.

FIG. 37 is similar to FIG. 34 for another illustrative embodiment.

FIGS. 38A and 38B are respectively similar to FIGS. 29A and 29B foranother illustrative embodiment.

FIG. 39 is similar to FIG. 30 for another illustrative embodiment.

FIG. 40 is similar to FIG. 32 for another illustrative embodiment.

FIGS. 41A and 41B are each similar to FIG. 33B for other illustrativeembodiments.

FIG. 42 is similar to FIG. 37 for another illustrative embodiment.

FIG. 43 is similar to FIG. 35B for another illustrative embodiment.

FIG. 44 is similar to FIG. 41B for another illustrative embodiment.

FIG. 45 is similar to FIG. 42 for another illustrative embodiment.

FIG. 46 is similar to FIG. 43 for another illustrative embodiment.

FIG. 47 is similar to FIG. 36 for another illustrative embodiment.

FIG. 48 is similar to FIG. 5 for another illustrative embodiment.

FIG. 49 is similar to FIG. 46 for another illustrative embodiment.

FIG. 50 is similar to FIG. 38A for another illustrative embodiment.

FIG. 51 is similar to FIG. 39 for another illustrative embodiment.

FIG. 52 is similar to FIG. 44 for another illustrative embodiment.

FIGS. 53A and 53B are each similar to FIG. 7 for other illustrativeembodiments.

FIG. 54 is similar to FIG. 35A for another illustrative embodiment.

FIG. 55 is similar to FIG. 13 for another illustrative embodiment.

FIG. 56 is similar to FIG. 16 for another illustrative embodiment.

FIG. 57 is similar to FIG. 56 for another illustrative embodiment.

FIG. 58 is similar to FIG. 57 for another illustrative embodiment.

FIG. 59 is similar to FIG. 55 for another illustrative embodiment.

FIG. 60 is similar to FIG. 54 for another illustrative embodiment.

FIG. 61 is similar to FIG. 51 for another illustrative embodiment.

FIG. 62 is similar to FIG. 44 for another illustrative embodiment.

FIG. 63 is similar to a portion of FIG. 53B for another illustrativeembodiment.

FIG. 64 is a simplified, partial, sectional view of an illustrativeembodiment of an assembly of several components in accordance with theinvention.

FIG. 65 is a simplified, partial, elevational view of an illustrativeembodiment of an assembly of several components in accordance with theinvention.

FIG. 66 is a simplified elevational view of an illustrative embodimentof a portion of a structure like that shown in FIG. 65 in accordancewith the invention.

FIGS. 67, 68A, and 68B are each similar to FIG. 66 for otherillustrative embodiments.

FIGS. 69A and 69B are each similar to FIG. 48 for another illustrativeembodiment.

FIG. 70 is similar to FIG. 50 for another illustrative embodiment.

FIG. 71 is similar to FIG. 61 for another illustrative embodiment.

FIG. 72 is similar to FIG. 47 for another illustrative embodiment.

FIG. 73 is similar to FIG. 65 for another illustrative embodiment.

FIGS. 74A-C are each similar to FIG. 65 for other illustrativeembodiments.

FIG. 75 is similar to FIG. 62 for another illustrative embodiment.

FIG. 76A is similar to FIG. 63 for another illustrative embodiment.

FIG. 76B is similar to FIG. 76A with another illustrative componentshown.

FIGS. 77A-G are simplified sectional views showing various illustrativeembodiments of leaflet attachment to other components of valves inaccordance with the invention.

FIGS. 78A and 78B are each similar to FIGS. like FIGS. 53A-B for otherillustrative embodiments.

DETAILED DESCRIPTION

As just one example of a context in which the present invention may beemployed, thousands of high-risk patients with severe aortic stenosis gountreated each year because they are deemed inoperable for a heart valvereplacement. In an attempt to treat these patients, collapsibleprosthetic heart valves have been developed to be inserted within thestenotic leaflets of these patients via percutaneous and/or trans-apicalmeans. However, known designs may not sufficiently address severalaspects of an optimal valve design, such as: (1) long-term durability,(2) mitral valve impingement, (3) perivalvular leakage, etc. Leafletattachment can be a key element when considering some of these issues.The designs disclosed herein provide these high-risk patients withsuperior valves by better addressing these and other issues.

FIGS. 1A-B provide a general overview of an illustrative embodiment of astent structure 10 that can be used in valves in accordance with thisinvention. These FIGS. show an expanded stent with independently flexingcommissure posts 20 a-c to reduce stress imparted to the valve leaflets(not shown). (Although this embodiment and several other embodimentshave independently flexing commissure posts, still other embodiments areshown that also increase valve durability and that have only partiallyor not independently flexing commissure posts.) The independent postsare partly separate from the anchoring structure 30 downstream from thepatient's valsalva sinus (upper portion of structure as viewed in FIGS.1A-B) and 40 adjacent the patient's native aortic valve annulus (lowerportion of structure as viewed in FIGS. 1A-B). In particular, upper freeend portions of posts 20 a-c are cantilevered from the annulus portion40 of stent 10. (Again, however, other embodiments may have onlypartially cantilevered or non-cantilevered commissure posts.)

FIGS. 2A-B show an illustrative embodiment of an expanded and contouredstent 10 with skirt flare 50 on base 40 and an extra-expanded section 30for the aorta. (Reference numbers are reused for generally similarfeatures in different FIGS. and different embodiments. Some FIGS. do notshow the rear or the complete rear of all structures to avoidover-complicating the depictions.) Attachment of leaflets (not shown) toposts 20 a-c and covering of the stent are important aspects of thisinvention.

FIGS. 3A-B show an illustrative embodiment of an expanded and contouredstent 10 with valve leaflets 60 a-c and buffer layer 70 and outer cuffmaterial 80. Note that commissure posts 20 can lie perfectly vertically,or alternatively they can be angled inwardly to bias the leafletsinwardly and thereby help to keep them from hitting the prosthetic valveframe and/or the surrounding patient anatomy during opening.

Attachment steps (in any order) after a stent 10 is at a predetermineddiameter and polished are generally the following:

-   -   Flexible leaflets 60 a-c (e.g., polymer sheet or pericardial        tissue sheet) are processed and cut to shape.        -   For example, tissue leaflets 60 a-c can be laid flat and            fixed with the use of glutaraldehyde or triglycidylamine            before being treated with an anti-calcification treatment            such as at least a 60% solution of ethanol.    -   Buffer material or materials 70 (e.g., polymer sheet or        pericardial tissue sheet) are processed and cut to shape.    -   Cuff material 80 (e.g., polyester fabric sheet) is formed into a        tube of the appropriate diameter and cut to length.    -   Cuff material 80 can cover the lower portion of stent 10, the        entire portion of where the leaflets are attached, and/or the        entire stent including an aorta section.    -   Intermediate materials of one or more layers (sheets) between        stent 10 and leaflet material 60 may be applied for attachment,        friction buffering, and tissue in-growth purposes. For example,        an interface between two polymer or tissue layers may be        beneficial, as compared to an unbuffered interface between        leaflets 60 and stent 10, for the above-mentioned reasons (e.g.,        less friction on and therefore wear of leaflets 60). Lubricious        polymer coating of the stent instead of just sheets may also be        incorporated.    -   Leaflets 60 are attached to stent 10 and around the        circumference of the stent base.

Specific details as to how the valve is assembled for different types ofstent posts 20 are given below.

FIG. 4A shows the flat and collapsed state of a stent model used tolaser-cut a part (stent) 10 from a tube (e.g., of a super-elastic metalsuch as nitinol or a balloon-expandable material such as cobaltchromium). FIG. 4B shows a round laser-cut part (stent) 10 in thecollapsed state. This stent embodiment has independent flexingcommissure posts 20 a-c that are solid except for one set of eyelets 22.Note, however, that these eyelets can be converted to any orifice shapesuch as an elongated slot.

FIGS. 5A-B show the flat and collapsed state of a stent model used tolaser cut a part (stent) 10 from a tube and a close-up of theindependent commissure posts 20 a-c. This stent 10 has independentflexing posts 20 a-c that are solid with two sets of eyelets 22.However, these eyelets could be converted to any orifice shape such aselongated slots. Note the bend line 52 of the skirt 50 and the base line54 of the stent discussed in connection with later FIGS.

FIG. 6 shows a buffering layer 70 that outlines the inner surface of astent 10 (actually stent portion 40) and posts 20 a-c to ensure thatthere is no contact between the leaflets 60 and any other material. Eachrectangular section 72 is sutured to the inner diameter of a respectiveone of posts 20. Top lip 74 covers the inner portion of the stent cellsabove bend line 52 (see also FIG. 5B). Bottom lip 76 covers the innerportion of the stent cells below bend line 52 to the bottom 54 of thestent (see also FIG. 5B). If section 78 is present, it can be wrappedaround the bottom edge 54 of the stent from the inner diameter to theouter diameter to be terminated at the bottom stent edge or farther up.Note that the triangular cut-outs 79 in this section allow for flexiblemovement of the edge and actually will meet when wrapped around thebottom edge, while the rounded extreme bottom edge sections 77 will meetto form one continuous circular path around the stent. The triangularcut-outs 79 also allow for a minimized chance of tearing duringexpansion and contraction of the valve.

FIG. 7 shows that the buffering layer 70 of this and all presenteddesigns in this invention disclosure can be made from three singlesections as shown in this FIG. (in contrast to one single piece as shownin FIG. 6).

FIG. 8 shows additional features that can be included in bufferingdesigns in accordance with the invention. (See FIG. 6 for generalfeatures that apply to all buffering designs of the invention.) Topflaps 71 wrap around the tops of the posts 20 from the inner diameter(ID) to the outer diameter (OD). Side flaps 73 wrap around the left andrights sides of each post 20 from the ID to the OD and are secured bysutures.

FIG. 9 shows that in areas of high complexity, individual bufferingstrips 70 of various sizes and shapes can be wrapped about the stentframe and sutured in place. FIG. 9 shows a generic rectangular strip 70as an example. A rectangular strip can be rolled to form a cylinder of adesired height to cover any portion of the stent as well.

FIG. 10 shows a single leaflet design 60 that is the foundation for manyof the following leaflet designs in this disclosure. Material 61 abovethe top-most horizontal dotted line is for redundant coaptation whereall three leaflets 60 a-c meet under back-pressure. (The various dottedlines are shown primarily for reference, although they can also actuallyappear on the leaflet (either temporarily or permanently) as a visualguide or aid for use during assembly of a valve.) Side flaps 62 bend atthe angled lines and provide an area to suture to the commissure post 20ID. Note that since the leaflet may be cut from a flat sheet, there maynot be a belly-shaped contour in the leaflet body 63; but when theangled side flaps 62 are attached to a vertical post 20, this allows forthe top portion of the leaflet to be closer to the central axis of thestent than the bottom portion, thus creating central coaptation. Sideflaps 62 wrap around the left and right sides of the commissure posts 20from the ID to the OD and are sutured down. Bottom flap 64 covers the IDportion of the stent cells below the bend line 52 to the bottom 54 ofthe stent. If this section is present, it can be wrapped around thebottom edge 54 of the stent from the inner diameter to the outerdiameter to be terminated at the bottom stent edge or farther up,depending on its length. Note that the triangular cut-out 65 in thissection allows for flexible movement of the edge and actually will meetwhen wrapped, while the rounded lower edge sections 66 will meet to formone continuous circular path around the stent. If desired, the materialalong curve 67 can be sutured down to form a natural belly shape for theleaflet. The bottom side flap 68 allows for some overlapping of adjacentleaflets to ensure that the inflow skirt edge is fully sealed.Triangular cut-outs 65 also allow for a minimized chance of tearingduring expansion and contraction of the valve.

FIG. 11 shows three single leaflets 60 a-c being attached to stent 10.The bottom flaps 64 and side flaps 62 can easily be seen beforeattachment occurs.

FIGS. 12A-C show three illustrative methods for leaflet and ancillarycomponent assembly. Each of these FIGS. shows a top view of a commissurepost 20 on the stent. (The commissure post is the large rectangle 20 ineach of these FIGS.) In FIGS. 12A and 12C the commissure post has asingle set of orifices 22. In FIG. 12B the commissure post has two setsof orifices 22 a and 22 b. In FIGS. 12A and 12B a buffering layer 70 isonly on the ID surface of the post (which is the upper surface as viewedin these FIGS.). In FIG. 12C buffering layer 70 is wrapped all the wayaround the post. Lines 60 a and 60 b illustrate representative leaflets,and the arrows at the top ends indicate that the leaflet materialcontinues beyond what is seen in the FIG. toward the central axis of thevalve. The dotted lines 90 indicate a suture passing through theeyelet(s) 22 and through the leaflets 60. Major features to note are asfollows: (1) a buffering layer 70 between the stent 10 and the leaflets60 reduces abrasion, (2) leaflets 60 are sutured together to minimizeany post gapping, (3) suture knots are on the OD of the post so as notto interfere with leaflet movement/abrasion, and (4) free ends 62 of theleaflets are curled back (e.g., toward the center of the valve) toprovide an additional buffering layer. Note that in FIG. 12C theleaflets can only be wrapped around the post from the ID to the OD (asat 62) if there is enough room between stent cells when the valve iscollapsed.

FIG. 13 shows that on the fabric covering 80 on the ID of the stentthere is a thin buffering material 70 to protect the leaflets 60 fromabrading against the other valve surfaces. The lack of post gapping andthe curled back leaflet edge before it is trimmed can be seen here at100 (see also FIG. 12A).

FIG. 14 shows how angled side flaps (62 of FIG. 10) allow leaflets 60a-c to coapt along the central axis 110. Note that under blood flowback-pressure, the leaflets will close tightly together with redundantcoaptation.

FIGS. 15A-B show two different valve variations that have a few keydifferences. FIG. 15A has a cuff and buffer section 70/80 that coversall of the expanding cells of stent portion 40. In FIG. 15B structure70/80 goes half of the way up the stent cells 40 to approximately thebend line 52, which may leave metal exposed for leaflet contact duringopening. FIG. 15A has a buffering layer and leaflets that terminate atthe lower edge 54 of the stent, whereas the buffering layer and leafletsof FIG. 15B completely wrap over the bottom edge 54 and are anchorednear bend line 52. Any or all of these features can be combined.

FIG. 16 shows that there is a complete seal from the leaflets 60 andbuffering layer all of the way from the stent ID around the edge of thestent base skirt to allow for a complete seal.

FIG. 17 shows that to allow for more transfer of leaflet load to thestent posts 20 (as opposed to almost entirely through point loads fromthe sutures 90 on the stent ID), sutures and/or leaflet material mayneed to be passed over the top of the post 20 and secured to the OD asindicated at 120.

FIGS. 18A-B show that to allow for more transfer of leaflet load(high-stress region 130 near leaflet free edge) to the stent post 20 (asopposed to almost entirely through point loads from the sutures 90),individual leaflets 60 a-c can be secured to caps 140 placed over thepost tops. Caps 140 can be made from fabric, polymer, and/or tissuecomponents.

FIG. 19 shows another single leaflet design in which many of the samefeatures as described in FIG. 10 can be utilized. The primary differencein this design is that the edge 62/64 is curled back onto the OD of theleaflet along the illustrated indicator lines 67/69, instead of foldedaround the base of the stent. So instead of the leaflet edge sealing forinflow of the stent skirt, this design forms a pocket underback-pressure, with no seams along the suture line. For a 3Dillustration see the next FIGS. As with the previous design, when theseflaps are folded back, the triangular sections 65 close so the leafletdoes not buckle. Since these flaps are folded back up against theleaflet OD, when the leaflet opens, the flaps 64 actually form a bufferbetween the upper base stent portion 40 and the leaflet.

FIGS. 20A-B shows 3D views of single leaflets 60. FIG. 20A is a top viewcross section, and FIG. 20B is a side view cross section. The arrowsindicate where the leaflet flaps 62/64 are folded back onto the leafletOD for one representative leaflet 60 b. Note that the curled-back designillustrated in FIGS. 12A-B is similar, except that in this design itruns along the entire edge 67/69 instead of just along the post.

FIG. 21 shows a flat cutout of a continuous leaflet 160. Instead ofthree single leaflets 60 a-c mating together to form an orifice 150,this design achieves this with one single continuous piece 160 ofleaflet material. The indicated edge 170 is sewn to the stent ID in asimilar manner as already described. Dashed line 180 indicates whereleaflet material 160 is creased to form a commissure and attached to apost 20. When the flat portion 190 of this design is pushed toward thecentral axis, it forms a belly as shown in the next FIG.

FIG. 22 shows a folded 3D illustration of continuous leaflets material160. See the above discussion of FIG. 21 for item descriptions.

FIGS. 23A-B show two methods for leaflet 160 and ancillary componentassembly. These are views similar to FIGS. 12A and 12C, with the samereference numbers used again for similar components. Major features tonote are as follows: (1) a buffering layer 70 between the stent 20 andthe leaflet material 160 reduces abrasion, (2) leaflets 60 (fromcontinuous leaflet structure 160) are sutured together to minimize anypost gapping, (3) suture knots are on the OD of the post 20 so as not tointerfere with leaflet movement/abrasion, and (4) bottom edge of theleaflets are curled back up toward the center of the valve to allow foran additional buffering layer (analogous to the folding along line 67 inFIGS. 20A and 20B). Note that the main difference in attachmenttechniques is that either the leaflet material 160 wraps around theentire stent post (FIG. 23A) if there is enough room between cells whenthe valve is collapsed, or the leaflet material 160 is folded on thepost ID only (FIG. 23B) in a continuous manner.

FIGS. 24A-B show the flat and collapsed state of a stent model used tolaser cut a part (stent 10) from a tube and a close-up of theindependent posts 20. This stent has independent flexing posts 20 thatare solid, with two sets of eyelets 22, and an open section 24 at thetop that forks (bifurcates) into two separate portions. See FIGS. 1-5for general features that are applicable to this and other designs.

A buffering layer 70 that can outline the ID of this stent 10 can beseen in FIGS. 6-8, but would have a fork-shaped top.

FIGS. 25A-B show single leaflet designs (with many of the same featuresas conveyed in FIGS. 10 and 19) that can be used for this stent design.The main difference is that the side flaps 62 have a slit 200 in themthat allows the flap to wrap around the OD of the fork (on both sides ofopen section 24) at the top of the stent post 20.

FIGS. 26A-B show two methods for leaflet 60 and ancillary componentassembly. Once again, these are views that are similar to FIGS. like 12and 23, with the same reference numbers being used again for similarcomponents. Major features to note are as follows: (1) a buffering layer70 between stent 10 and leaflets 60 reduces abrasion, (2) leaflets 60are sutured together (using sutures 90) to minimize any post gapping,(3) suture knots are on the OD of the post 20 so as not to interferewith leaflet movement/abrasion, (4) free ends 62 of leaflets 60 arecurled back toward the center of the valve to provide an additionalbuffering layer in FIG. 26A, (5) the gap 24 between forked posts 20 isjust large enough for leaflet thicknesses to eliminate post gapping, and(6) the leaflets attached to the OD as in FIG. 26B allow for stressescaused from blood flow back-pressure to be transferred to the stentframe 10 instead of point loads at suture attachments.

FIG. 27 shows a 3D view of individual leaflets 60 and the top portion202 of the side flaps (above slit 200 in FIG. 25A or 25B) that wraparound the forked top section of the stent post 20.

FIG. 28 shows that another variation of this stent design is toeliminate the eyelets 22 on the lower portion of posts 20. If there areno orifices to attach the leaflet flaps 62 to the posts, the leafletflaps can be sutured together along the length of this lower sectionand/or through cuff material surrounding the expandable stent portion.

FIGS. 29A-B show the flat and collapsed state of a stent model used tolaser cut a part (stent 10) from a tube and a close-up of theindependent posts 20. This stent has independent flexing posts 20 thatare open in the middle 24 (i.e., bifurcated) with two sets of eyelets22. It also has a terminating single eyelet 26 for anchoring the leafletbase and other materials. See again FIGS. 1-5 for general features thatare applicable to this and other designs.

FIG. 30 shows an example of a design variation with the non-expandingopen stent post 20 and flared skirt 50.

FIG. 31 shows a close-up of the flat and collapsed state of a stentmodel used to laser cut a part (stent 10) from a tube with independentcommissure posts 20. This stent has independent flexing posts 20 thatare open in the middle (i.e., at 24), with two sets of eyelets 22.Additionally, this design has a connection 28 higher up on the stentposts 20, thus making the posts less cantilevered and therefore possiblyless flexible if needed. However, the valve assembly is not disruptedwhen internally mounting the leaflets through the center slot 24 of thestent posts. See again FIGS. 1-5 and 29 for general features that areapplicable to this and other designs.

FIG. 32 shows a buffering layer design including features that can be inaddition to those shown in FIG. 6. Rectangular flaps 72 outline the IDof stent posts 20. An “I” shaped slit 210 is cut through material 70 andthe resulting flaps are wrapped through the middle portion 24 of thestent post 20 from the ID to the OD, then secured in place.

FIGS. 33A-B show single leaflet designs, with many of the same featuresas conveyed in FIGS. 10 and 19, which can be applied to this stentdesign. The main difference is that the entire side flaps 62 passthrough the middle slot (24 of FIG. 29) and around to the OD, where itis secured (see next FIG.).

FIG. 34 shows one method for leaflet and ancillary component assembly.Once again, this is a view similar to FIGS. like 12 and 23, with thesame reference numbers being used again for similar elements. Majorfeatures to note are as follows: (1) a buffering layer 70 between thestent 10 and the leaflets 60 reduces abrasion, (2) the gap 24 betweensides of the post 20 is just large enough for leaflet thicknesses toeliminate post gapping, (3) suture knots (associated with sutures 90)are on the OD of the post 20 so as not to interfere with leafletmovement/abrasion, and (4) the leaflets 60 attached to the OD of posts20 allow for stresses caused by blood-flow back-pressure to betransferred to the stent frame instead of point loads at sutureattachments.

FIGS. 35A-B show an example of this type of design with single leaflets60 pulled through a center slot 24 and wrapped around to the OD of thestent post 20. Also note that the buffering material 70 and leaflets 60wrap slightly around the stent base as indicated at 220. In some areasthese FIGS. show the leaflet material as though transparent.

FIG. 36 shows a flat cutout of a continuous leaflet 160. Instead ofthree single leaflets 60 mating together to form an orifice 150, thisdesign achieves this with one single continuous piece 160. The indicatededge 170 is sewn to the stent ID in a similar manner as alreadydescribed. Dashed lines 180 indicate where one representative commissureof the leaflets is creased and pulled through the central slot 24 of thepost 20. When the flat portion 190 of this design is pushed toward thecentral axis, it forms a belly as shown in previous FIGS.

FIG. 37 shows one method for leaflet and ancillary component assembly.Again, FIG. 37 is a view similar to FIGS. like 12 and 23, and the samereference numbers are used in all FIGS. of this type to indicate similarcomponents. Major features to note are as follows: (1) a buffering layer70 between the stent 10 and the leaflets 160 reduces abrasion, (2) thegap 24 between sides of the post 20 is just large enough for leafletthicknesses to eliminate post gapping, (3) suture knots (associated withsutures 90) are on the OD of the post 20 so as not to interfere withleaflet 160 movement/abrasion, (4) the leaflets 160 attached to the OD(at 180) allow for stresses caused from back-pressure to be transferredto the stent frame 10 instead of point loads at suture attachments, and(5) the leaflet 160 is fully sealed at the commissures 20.

FIGS. 38A-B show the flat and collapsed state of a stent model used tolaser cut a part (stent 10) from a tube and a close-up of theindependent commissure posts 20. This stent has independent flexingposts 20 that are open in the middle 24 with two sets of eyelets 22.Additionally, this design has an opening 28 at the bottom of the slot24, which allows the post 20 to expand into a triangular shape. Seeagain FIGS. 1-5 for general features that are applicable to this andother designs.

FIG. 39 shows an example of a stent variation with a central verticalslot 24 when in a collapsed state that was formed into a triangularopening 24/28 in an expanded state. The triangular opening of this post20 more closely mimics the contoured shape of a native valve than, say,a vertical non-expanding post.

FIG. 40 shows a buffering layer design including features that can be inaddition to those shown in FIG. 6. The upwardly extending post flaps 72outline the ID of stent posts 20 when those posts are expanded into atriangular shape (e.g., as shown at 24/28 in FIG. 39). A slit 210 is cutthrough buffering material 70 and the resulting flaps are wrappedthrough the middle portion 24/28 of the stent posts 20 from the ID tothe OD, then secured in place.

FIGS. 41A-B show single leaflet designs, with many of the same featuresas conveyed in FIGS. 10 and 19, which can be applied to this stentdesign. The main difference is that the side flaps 62 at the commissuresare spread apart (due to the triangular stent post opening 24/28), thusadditional sealing measures are needed.

FIG. 42 shows one method for leaflet and ancillary component assembly.This is yet another FIG. similar to FIGS. like 12 and 23, and which usesthe same reference numbers for similar elements. In addition, line 230indicates a patch having the same or similar material properties aselements 70 or 60 that seals the triangular opening 24/28 in the posts20. Major features to note are as follows: (1) a buffering layer 70between the stent 10 and the leaflets 60 reduces abrasion, (2) sutureknots (associated with sutures 90) are on the OD of the post 20 so asnot to interfere with leaflet movement/abrasion, (3) the leaflets 60attached to the OD via flaps 62 allow for stresses caused fromback-pressure to be transferred to the stent frame 10 instead of pointloads at suture attachments 90, and (4) the triangular-shaped posts20/24/28 more closely mimic the contour shape of a native valve, thusfunctioning more optimally.

FIG. 43 shows an example of a stent variation with an open expandingpost 20 that results in a triangular commissure area 24/28 that moreclosely mimics the contour shape of a native valve. A patch 230 issutured through the eyelets 22 and around the base of the stent 10 toensure a sealed environment. Note also that there is a double layer ofcuff material 80 on the stent OD to aid in better sealing and tissuein-growth when pushed against native aortic root tissue.

FIG. 44 shows a single leaflet design, with many of the same features asconveyed in FIG. 10, which can be applied to this stent design. The maindifference is that one side flap 62 has an extension 162 that is used toseal the triangular-shaped opening.

FIG. 45 shows one method for leaflet and ancillary component assembly.This is again similar to FIG. 42, and the same reference numbers areused for similar elements in both of these FIGS. Major features to noteare as follows: (1) a buffering layer 70 between the stent 10 and theleaflets 60 reduces abrasion, (2) suture knots are on the OD of the post20 so as not to interfere with leaflet movement/abrasion, (3) the gap 24is large enough for leaflet thicknesses to eliminate post gapping, (4)the leaflets 60 attached to the OD of post 20 allow for stresses causedfrom blood flow back-pressure to be transferred to the stent frame 10instead of point loads at suture attachments 90, and (5) the doublingback of the one leaflet at 162 aids in sealing the triangular stent postopening 24/28.

FIG. 46 shows an example of a single leaflet design with an enlargedtriangular side flap 162 that is doubled back over itself to aid insealing the triangular expanded post opening 24/28. FIG. 46 omitsdepiction of the sutures that are typically used to secure the leafletand flap material to the stent frame.

FIG. 47 shows a flat cutout of a continuous leaflet 160 with severalfeatures that aid in the attachment and sealing for an expanding post20/24/28 design. Flaps 240 with triangular cutouts 242 are wrappedaround the base of the stent 10. Edge 250 is sutured to the stent 10 toform the base of the leaflet belly. Edge 244 is secured around the baseof the stent 10. Sections 260 are pulled through the triangular postopening 24/28, folded around the OD of the post 20, and doubled back onthemselves. Sections 262 cover up the triangular openings 24/28. Flaps270 extend toward the base of the stent to enhance sealing of covers 262and are joined to the other flaps 240 along their edges 246 and 276. Seethe next FIG. for more detail.

FIG. 48 shows one method for leaflet and ancillary component assembly.This is again similar to FIG. 45, and again uses the same referencenumbers for similar elements. Major features to note are as follows: (1)a buffering layer 70 between the stent 10 and the leaflets 160 reducesabrasion, (2) the gap 24 between sides of the posts 20 at the upper apexof the triangular stent post opening is just large enough for leafletthicknesses to eliminate post gapping at that location, (3) suture knotsare on the OD of the post 20 so as not to interfere with leafletmovement/abrasion, (4) the leaflets 160 attached to the OD of post 20allow for stresses caused from blood flow back-pressure to betransferred to the stent frame 10 instead of point loads at sutureattachments 90, and (5) the leaflets 160 are fully sealed at thetriangular commissures 20/24/28 as indicated at 262.

FIG. 49 shows an example of a single leaflet design doubled over itselfat the edges 260 with a triangular section 262 in the middle to achievea continuous tight seal.

FIG. 50 shows further development of structures like those shown inFIGS. 5A and 5B. FIG. 50 shows a combination of eyelets 22 and slots 23(already mentioned as a possibility earlier in this specification). Thetop and bottom post eyelets 22 anchor the leaflets 60 into position, andthe slots 23 allow for easier assembly and multiple passes of astitching needle. FIG. 50 shows the metal structure 10 in a flat orplanar depiction and in its collapsed condition or configuration. Again,there is a combination of eyelets 22 and slots 23 on the commissureposts 20 for leaflet 60 attachment. Eyelets 21 in other areas can bevariously used to attach leaflets 60, cuff material 80, and/or bufferingmaterial 70. FIG. 51 shows the FIG. 50 structure in its expanded state.

FIG. 52 shows an illustrative simplification of a single leaflet designof the general type that is shown in FIGS. 10 and 19. This simplifiedversion allows the technician to assemble and trim the valve as needed,since there can be a variability in how the tissue behaves. This designalso reduces the amount of openings to enhance sealing. The sameprinciples apply as are discussed above in connection with FIGS. 10 and19. Note also that this design can be used for FIGS. 10 and 19 valves,and then trimmed to the shape of the stent 10 if needed.

FIGS. 53A and 53B show further development of structures of the typethat are shown in FIGS. 12A-C. In particular, FIGS. 53A and 53B show thefront (outer diameter) view of a straight solid commissure post 20 andsuture attachment 90 a and/or 90 b for leaflets 60. Note that thesebasic concepts can be used on the other post designs. FIG. 53A showssutures 90 a only looped around the stent material in the verticaldirection. FIG. 53B shows sutures 90 a in the vertical direction andsutures 90 b in the horizontal direction, which is more indicative ofwhat is shown in the top views of FIGS. 12A-C.

FIGS. 54-57 show further development of structures of the general typeshown in FIGS. 13-16. FIGS. 54-57 are examples of modified stents 10with tissue structures added. FIG. 54 is a side view of a valve withtissue leaflet 60 attachment like FIG. 53A. FIG. 55 is a top viewsimilar to FIG. 13, but with tissue leaflets 60. FIG. 56 is a bottomview with leaflet tissue wrapped around the bottom edge. (This leaflettissue may also be over other layers of fabric and/or buffer material,depending on the design of the valve.) FIG. 57 is a bottom view withtissue terminated at the bottom edge. Note also that the traces 300 forthe leaflet shape are shown. These traces 300 can be temporary (orpermanent) markings on the leaflet material to help the assemblytechnician properly shape and assemble the valve.

FIGS. 58-60 show further development of structures like those shown inFIG. 20. FIGS. 58-60 show valves built with this concept to furtherclarify how the valve actually looks. FIG. 58 is a bottom view ofleaflets folded to form pockets when the free edges of the leaflets arecoapting. FIG. 59 is a top view showing continuous pockets 310. FIG. 60is a side view showing continuous pockets 310 and the rolled up leafletstrimmed to the outline of the stent at 320. Buffer and cuff material canalso be shaped to outline the contour of the expandable stent portion.

FIG. 61 shows further development of structures like those shown inFIGS. 30 and 31. FIG. 61 shows a further developed version of a nitinolpart (stent) 10 that has been expanded. This design also incorporateseyelets 22 and slots 23, as well as eyelets 21 in various locationsaround the stent for attachment. Note that this design also has an extrarow of closed-perimeter, open-centered, circumferentiallycollapsible/expandable cells on the bottom section 40/50 as compared tothe earlier examples.

FIG. 62 shows a single leaflet shape 60 which may have severaladvantages. For example, as compared to some leaflet shapes describedearlier in this specification, the FIG. 62 shape can reduce the amountof leaflet tissue that needs to be collapsed when the prosthetic valveis collapsed. This can help the prosthetic valve collapse to a smallersize for less invasive delivery into a patient. This leaflet shape canalso help to redistribute high stress areas in the base of the valvebelly where tear-out might otherwise tend to occur. All of thesemodifications can improve valve function and durability.

As in some earlier-described embodiments, lines 300 are indicator lineson leaflet 60 to help with assembly of the leaflet into a prostheticvalve. In addition, some of these lines serve to demarcate certainportions of the leaflet in the following discussion. Line 300 a-b is aline along which leaflet material outside the line can be folded in onleaflet material inside the line. Especially line 300 b is also a linealong which the base of the leaflet may be sutured to other structure ofthe valve. For example, this may result in securing the base of theleaflet through cuff material 80 of the valve. This arrangement helps todistribute stresses at the base of the leaflet (e.g., in the areaindicated generally by reference number 400) upwardly along curve 300 b(e.g., into the areas indicated generally by reference number 410) tospread out these stresses and prevent them from concentrating right atthe leaflet base. For example, FIG. 64 shows how leaflet material 62 boutside indicator line 300 b may be folded up outside the remainder of aleaflet 60. This produces a doubled-over layer of leaflet material,which can be sutured through (including to other structure of the valve)using sutures 90 to improve durability.

Returning to FIG. 62, and also now referring to a representativeprosthetic valve commissure post 20 as shown in FIG. 63 for use with theFIG. 62 leaflet, leaflet flap portion 62 a may be positioned relative topost 20 so that portion 62 a sits above the top-most horizontal eyelet23 a in post 20. Leaflet flap portion 62 c is then positioned betweenhorizontal eyelet 23 a and the top-most vertical eyelet 23 d in post 20.Below flap section 62 c is a further leaflet flap section 62 d, which ispositioned for attachment (e.g., via sutures) to three vertical eyelets23 d in the upper portion of stent post 20. Dotted line 420 in FIG. 63indicates the approximate boundary of leaflet flap portion 62 d whenthus secured to post 20. The area of post 20 below eyelets 23 d can beused as additional area for, e.g., cuff 80 attachment, hiding sutureknots, and other features.

As compared to some earlier-described leaflet embodiments, the FIG. 62leaflet can include less leaflet material outside indicator line 300 b.As noted earlier, this can help reduce the amount of leaflet material inthe valve and thereby facilitate collapsing the valve to a smallercircumferential size.

Turning now to another consideration that may be important inconstruction of prosthetic heart valves in accordance with theinvention, when a leaflet 60 is secured through cuff material 80, it maybe desirable to ensure a durable securement of the leaflet with reducedmovement that could lead to cuff/suture/leaflet abrasion. Termination ofa cuff 80 (especially when the stent is flared outward as at 50 in someembodiments herein) can be difficult. FIG. 65 and several subsequentFIGS. show structures that can help to address these issues.

As shown in FIG. 65, cuff 80 is secured by outlining the struts of thecells that form stent portions 40 and 50 with whip stitch sutures 90 a.In addition, stent portions 40 and 50 are constructed so that theyinclude several annularly extending serpentine, undulating, or zig-zagmembers 42 a-c that are connected to one another by vertical bars 44.Serpentine members 42 a-c annularly compress or expand to allow theprosthetic valve to circumferentially collapse or expand. But verticalmembers 44 do not change length during such annular compression orexpansion of the serpentine members. This helps to reduce the amount bywhich the prosthetic valve changes axial length during circumferentialcompression or expansion. This in turn can help reduce any tendency ofcuff 80 to shift relative to stent portion 40/50. Vertical bars 44 canalso be secured to cuff 80 by suture stitches 90 b. In this example,cuff 80 and buffer material (hidden between the fabric of cuff 80 andleaflets 60) are mounted in the inside diameter (“ID”) of the stent andcan extend any distance up or down the height of the stent frame.(Although FIG. 65 shows all of components 20, 42, and 44 one-piece withone another, some or all of these components may initially be separatefrom one another and then assembled with the other components.)

In addition to the above, the invention can address possible difficultyin firmly securing cuff 80 to stent cell ends. For example, especiallywhen stent portion 40 is flared as at 50, the adjacent cuff material 80may have a tendency to slip vertically along the stent when a leaflet 60is secured to the cuff material and under load. Reference number 440 inFIG. 65 points to a representative location where this may be an issue.Passing a suture through an eyelet 91 at such a location 440 can helpprevent material slip. FIGS. 66-68 also show several others shapes thatcan be provided at the top and/or bottom of stent cells to help securethe cuff 80 to the stent more securely. For example, FIG. 66 showsproviding an enlarged knob 450 on the end of a representative stent cell40/50. Knob 450 is connected to the stent cell by a small neck region452. Suture material 90 can be wound around neck 452 as shown in FIG. 66to help prevent any other material that is secured to the stent bysuture 90 from moving upwardly (in this example) away from the depictedstent cell end.

As another example, FIG. 67 shows a notch 460 in the stent material,which notch opens away from the associated stent cell end 40/50. Suturematerial 90 can pass (repeatedly) from the stent cell end through notch460 and back into the stent cell end to ensure that the suture (andanything secured by the suture) cannot shift upwardly (in this example)relative to the stent cell end.

As still another example, FIG. 68A shows a partially formed eyelet 470at the end of a stent cell 40/50. Eyelet 470 is large enough for suturematerial 90 to pass through, but it may not be large enough for thesuture needle to pass through. However, suture material 90 can be pulledinto eyelet 470 through the open side 472 of the eyelet (which open sidefaces away from the apex or end of stent cell 40/50). Suture material 90may pass (repeatedly) from inside stent cell 40/50 through eyelet 470and back into stent cell 40/50 in a loop, FIG. 8, or other pattern tosecure suture 90 and any other material (such as cuff 80) that isengaged by suture 90 to the end of the stent cell. Again, as in the caseof the structures shown in FIGS. 66 and 67, this is done in such a waythat other material (such as cuff 80) that is secured by suture 90cannot move upwardly (in this example) relative to the end of stent cell40/50.

FIG. 68B shows an alternative to FIG. 67 in which the suturing 90 isinterlocked with itself as part of passing through notch 460. Theinterlocking shown in FIG. 68B can also be used with other stent frameshapes such as the shape shown in FIG. 68A.

FIG. 69A shows a possible modification of a structure like that shown inFIG. 12B. In this alternative a reinforced core 500 a or 500 b lines thecreased area that the flaps of leaflets 60 a and 60 b are folded around.The core material 500 a/b can be other tissue, polymer, metal, and/orfabric. The flap of the leaflet 60 a or 60 b is sutured (90 a or 90 b)through the stent 20 in a manner similar to what has already been shown.The flaps of the leaflets 60 a and 60 b can be additionally wrappedaround the core(s) 500 a/b and secured via additional suturing 510 toform a bundle. This may add more reinforcement from tissue tears and mayalso mitigate leaflet abrasion as illustrated by FIG. 69B. By bindingthe leaflet (e.g., 60 b) and core (e.g., 500 b), the leaflet is notallowed to open all of the way up to hit the frame 10 of the stent. Inother words, a clearance like that indicated by double-headed arrow 520in FIG. 69B is maintained.

FIG. 70 shows an example of a self-expanding stent design with thedownstream-most connections 530 between commissure posts 20 and theremainder of annulus portion 40 more than 50% up the post height in thedirection of blood flow through the implanted valve. This means that inthis embodiment the posts 20 are less cantilevered than in some otherembodiments. This design still retains the ability to attach theleaflets to other structure of the valve in ways similar to what hasbeen described for other embodiments.

FIG. 71 shows an example of a balloon-expandable stent design with thedownstream-most connections 530 between each stent post 20 and theremainder of the stent 10/40 all the way up to the top of the posts 20.FIG. 71 shows stent 10 in its fully expanded state. This design stillretains the ability to attach the leaflets of the prosthetic valve toother structure of the valve in ways that are similar to what is shownand described for other embodiments. The FIG. 71 stent includesattachment structures 470/472 at the base of the stent that are similarto what is shown in FIG. 68. These can also be used as interlocks forattachment of the prosthetic valve to a delivery system for that valve.

FIG. 72 shows another example of one continuous sheet 160 of leafletmaterial that can be shaped (when attached to a valve stent, etc.) toprovide all three leaflets of a valve. FIG. 72 thus shows an alternativeto what is shown in other FIGS. like FIG. 21. This continuous design hasflaps 540 built in to attach to the tops of the commissure posts 20 asdescribed elsewhere in this specification. Another difference isradially inward contour or bulge of the free edge 61 of what will beeach leaflet. This bulge gives the leaflets additional coaptation whenthe valve is closed.

FIG. 73 illustrates the point that several of the principles of thisinvention can be applied to collapsible and re-expandable prostheticvalves that use leaflets that are not just from sheet material. Forexample, a bovine jugular or porcine aortic root (or individualleaflets) 550 can be attached to the commissure posts 20 of a valvestent. In other words, in the prosthetic valve shown in FIG. 73, thevalving action is provided by the inclusion of an intact tissue valve(or leaflet cusps) 550 taken from an animal.

FIGS. 74A-C show several illustrative variations on what is shown inFIG. 65. For example, in FIG. 74A reference line 560 a indicates thecontour of one representative leaflet where it is attached (near itsbottom or upstream portion) to the cuff 80 of the valve. (Apart fromreference line 560 a, FIG. 74A omits leaflets 60 and does not attempt toshow the rear of the structure. Reference line 560 a is shown primarilyfor purposes of explanation. This line does not itself depict structure,but rather is primarily just for geometric reference. The same is truefor reference lines 560 b and 560 c in later FIGS.) FIG. 74A may show aballoon-expandable valve with a fabric cuff 80 and a porcine tissuebuffer layer (hidden on the inside diameter (“ID”) of fabric 80)attached to about 75% of the height of the annulus portion 40 of thestent (i.e., the lower 75% of the annulus portion 40 height). (Stentportion 40 may be called the annulus portion because it is typicallyimplanted in or near the annulus of the patient's native heart valveannulus.) Reference line 560 a in FIG. 74A shows the lower portion ofthe leaflet attached straight across from the bottom eyelet 22 of onecommissure post 20 to the next commissure post 20. See also FIG. 75,which shows an example of such a leaflet 60 with reference line 560 asuperimposed on it.

FIG. 74B may show a self-expanding valve with the fabric cuff 80 andporcine tissue buffer (hidden on ID of the fabric) attached to the fullheight of the annulus portion 40 of the stent. As indicated by thereference line 560 b, a typical leaflet 60 is attached part of the wayup the posts 20, and the belly section of the leaflet gradually contours(curves) toward the stent base below the posts (see also FIGS. 76A-B,which are discussed below).

FIG. 74C may show a self-expanding valve with the fabric cuff 80 on theoutside diameter (“OD”) of the stent and porcine tissue buffer (notvisible) on the ID of the stent. (Note that FIG. 74C shows cuff 80 asthough transparent, and that this FIG. omits depiction of the suturesthat are typically used to secure cuff 80 to the stent frame.) As shownby the reference line 560 c, a typical leaflet 60 in this case isattached near the bottom of the posts 20, and the leaflet belly sectiongradually contours toward the stent base, at which point it can beattached to the base of the stent, cuff 80, and features like thoseshown in FIGS. 66-68.

FIGS. 76A-B show an illustrative variation of a commissure post 20(e.g., as in FIG. 63) and the matching leaflet 60 (e.g., as in FIG.74B). From FIGS. 76A-B it can be seen how the leaflet 60 matches up withvarious features of the stent post 20 as described earlier (e.g., inconnection with FIG. 74B). Note that the two bottom eyelets 23 e are notneeded for leaflet attachment, but are present for cuff 80 securement.Also, the pair of eyelets 23 d′ are placed slightly farther apart thanthe eyelet pairs above to aid in the transition of the leaflet contour(curve).

FIGS. 77A-G illustrate several ways that leaflets can be assembled toother components of the valve. Whereas FIGS. like 69A-B focus on thearea of leaflet attachment to commissure posts 20, FIGS. like 77A-G canapply to leaflet attachment elsewhere than at commissure posts 20. Ineach of these FIGS. the double vertical lines represent any desiredarrangement and/or combination of elements like stent 10 (e.g., annulusportion 40), buffer layer 70, and/or cuff layer 80. Element 60 isleaflet material, element 90 is suture material, and element 500 is areinforcing core (e.g., as in FIGS. 69A-B). The bottom portion 570 of aleaflet 570 can be folded and/or supported with core material 500 tocreate a stronger seam. This seam can then be secured to the cuff 80and/or stent 10/40 via suture 90 using a variety of techniques. Forexample, the stitch 90 shown in FIG. 77A pierces through the layers ofleaflet tissue 60/570 once and whips around the bottom. The stitch shownin FIG. 77B pierces through the layers of tissue 60/570 twice. Areinforced core 500 (FIGS. 77C-F) can be placed inside the foldedleaflet 60/570. The leaflet (main portion 60) can be folded between thecuff 80 and the core 500 as shown in FIG. 77C. Alternatively, the mainportion of the leaflet 60 can pass in front of the core 500 as shown inFIG. 77D. With the addition of a core 500, the leaflet 60 may not needto be folded at all, but may simply be attached to the front/back of thecore as shown in FIGS. 77E and 77F, respectively. Yet another option isto use a foldable core material 580, by which to sandwich the end of theleaflet 60 as shown in FIG. 77G. As noted earlier (e.g., in connectionwith FIGS. 69A-B), the material of a reinforcing core can be othertissue, polymer, metal and/or fabric. Thus a reinforcing core like 500or 570 can be rigid (e.g., metal or the like) or soft (e.g., fabric,tissue, or the like). The reinforcement can run along dotted suturelines shown on the leaflets in some of the FIGS. herein (e.g., line 575in FIG. 76B) or any portion of such a suture line. Rigid reinforcementmembers may have eyelets parallel and/or perpendicular to post 20eyelets.

FIGS. 78A and 78B show some examples of suture patterns that may be usedto attach leaflet flaps to commissure posts 20. In FIG. 78A one suture90 is used to attach a leaflet flap to a post 20. Beginning at thebottom right eyelet, the suture 90 is temporarily anchored at or near590 where a suture tail remains. Suture 90 then runs from the bottomeyelet 23 to the top (back and forth through successive eyelets and aleaflet flap (not shown)) and then returns back down the same side(again back and forth through successive eyelets and the above-mentionedleaflet flap). Suture 90 then crosses over near 590 to the other columnof eyelets to repeat the same pattern. Ultimately the suture end is tiedoff to the suture tail at 590.

In the alternative shown in FIG. 78B, each side of the post eyelets(i.e., the left side eyelets or the right side eyelets) are suturedindependently (suture 90 a starting from 590 a on the left, and suture90 b starting from 590 b on the right), and each suture is ultimatelytied off to its own tail at 590 a or 590 b, respectively.

To some extent the appended claim terminology may differ fromterminology used up to this point in this detailed description. Somespecific examples of what certain claim terms refer to are as follows.Supporting structure 10; sheet-like, flexible, leaflet member 60/160;free edge portion of a leaflet 61; flexible chord across an interior ofthe supporting structure (see, for example, reference number 131 in FIG.18A or FIG. 20A; such a chord is typically not a straight chord, butrather a loose and flexible chord); material of the leaflet beyond anend of the chord forming a flap 62; cylindrical surface defined by oneof the inner and outer surfaces of the supporting structure (suchcylindrical surfaces are abstract geometric shapes defined by what areearlier referred to, respectively, as the ID (inside diameter) and OD(outside diameter) of supporting structure 10; these cylindricalsurfaces are not necessarily round, but may instead have other shapessuch as oval, elliptical, etc.); suture 90; inner surface of thesupporting structure (ID of supporting structure 10); outer surface ofthe supporting structure (OD of supporting structure 10); secured lineportion(s) 67/170/250/300 b; belly portion of the leaflet 63/190/310;additional material of the leaflet beyond the secured line portion awayfrom the belly portion forming a second flap 64/240/270/62 b; axial endof the supporting structure, e.g., lower end of structure 10 as viewedin FIG. 1a ; sheet-like, flexible, buffer material 70; annularly spacedcommissure posts 20 a-c; cantilevered from other structure of thesupporting structure, e.g., commissure posts 20 may have upper free endportions and are only attached to the remainder of supporting structure10 below those upper free end portions (this cantilevering of the upperfree end portions of the commissure posts gives the commissure postswhat is sometimes referred to herein as independent flexibility, whichmeans, for example, that the upper free end portion of a commissure postcan flex radially inwardly and outwardly at least somewhat independentlyof other portions of supporting structure 10) (note that in FIG. 65 theposts 20 are not cantilevered, but the entire stent frame flexes toreduce stress); commissure post bifurcated into two spaced apartmembers, e.g., the commissure post portions on opposite sides of notchor opening 24; annular, annularly collapsible and re-expandablesubstructures 42 a-c that are spaced from one another along an axisabout which the supporting structure is annular; linking members 44 thatare substantially parallel to the above-mentioned axis and thatinterconnect the above-mentioned substructures 42 a-c; sheet of flexibleleaflet material 160 having a central opening 150 with three sides 61;leaflet-linking areas 180; the sheet 160 continues radially outwardlybeyond at least a portion of at least one of the secured line portions250 to form a flap 240/270; a plurality of members disposed in a zig-zagpattern, e.g., 42 c, that extends in a direction that is annular of thesupporting structure; at least two of the members (e.g., the two membersthat meet at 440) meeting at an apex 440 that points away from thesupporting structure parallel to an axis about which the supportingstructure is annular; a sheet of flexible material 70 and/or 80 securedto the supporting structure; a plurality of flexible leaflets 60/160;suture attachment 90 at the apex 440; the apex 440 includes an eyelet21; an enlarged head 450 on the end of a reduced neck 452; a notch 460;the notch is narrowed near its entrance 462. The examples for certainclaim terms provided in this paragraph are only illustrative. As justone example of this, not all of the reference numbers that are used forcertain features and elements in certain FIGS. are repeated in everyFIG. for every reoccurrence of the same or similar features or elements.

It will be understood that the foregoing is only illustrative of theprinciples of the invention, and that various modifications can be madeby those skilled in the art without departing from the scope and spiritof the invention. For example, the number of cells employed in thestents in valves in accordance with the invention can be different fromthe numbers shown in the various illustrative embodiment describedabove.

The invention claimed is:
 1. A prosthetic heart valve comprising: anannularly collapsible and re-expandable supporting structure extendingbetween an inflow end and an outflow end, the supporting structureincluding a plurality of struts; a plurality of leaflets disposed insidethe supporting structure; a cuff disposed on a surface of the supportingstructure; a plurality of commissure features for attaching the leafletsto the supporting structure; a plurality of first eyelets disposed onthe supporting structure, the first eyelets being disposed adjacent theinflow end at a position farthest from the outflow end, and spaced fromthe plurality of commissure features, selected ones of the plurality offirst eyelets being coupled to the cuff.
 2. The valve defined in claim1, wherein the supporting structure further comprises a plurality ofvertices at the inflow end, and each of the plurality of verticesclosest to the inflow end includes at least one first eyelet.
 3. Aprosthetic heart valve comprising: an annularly collapsible andre-expandable supporting structure extending between an inflow end andan outflow end, the supporting structure including a plurality ofstruts; a plurality of leaflets disposed inside the supportingstructure; a plurality of commissure features for attaching the leafletsto the supporting structure; a plurality of first eyelets disposed onthe supporting structure, the first eyelets being disposed adjacent theinflow end and spaced from the plurality of commissure features; and aplurality of second eyelets disposed on the supporting structure at theoutflow end.
 4. The valve defined in claim 3, wherein the supportingstructure further comprises a plurality of vertices at the outflow end,and at least one of the plurality of vertices closest to the outflow endincludes at least one second eyelet.
 5. The valve defined in claim 1,wherein the plurality of flexible leaflets includes three leaflets. 6.The valve defined in claim 1, wherein each of the plurality of firsteyelets is circular.
 7. The valve defined in claim 1, further comprisinga material disposed around the supporting structure near the inflow end,the material being coupled to the supporting structure via the pluralityof first eyelets.
 8. The valve defined in claim 7, wherein the materialcomprises a fabric.
 9. The valve defined in claim 7, wherein thematerial comprises a tissue.
 10. The valve defined in claim 1, whereinthe supporting structure includes a plurality of diamond-shaped cellsarranged in rows, and the plurality of first eyelets are disposed onselected vertices of the diamond-shaped cells.
 11. A stent for aprosthetic heart valve comprising: an annularly collapsible andre-expandable supporting structure extending between an inflow end andan outflow end, the supporting structure including a plurality ofstruts; a plurality of commissure features for attaching leaflets to thesupporting structure; and a plurality of first eyelets disposed on thesupporting structure adjacent the inflow end, each of the plurality offirst eyelets being spaced from the plurality of commissure features;wherein the supporting structure includes a plurality of diamond-shapedcells arranged in rows, each of the plurality of diamond-shaped cellshaving four vertices, and the plurality of first eyelets are disposed onselected vertices that are farthest from the outflow end.
 12. The stentdefined in claim 11, wherein the stent includes an aortic section havinga first maximum diameter, and an annulus section having a second maximumdiameter, the first maximum diameter being larger than the secondmaximum diameter.
 13. The stent defined in claim 12, wherein the annulussection tapers radially outward so as to have an increasing diameterfrom a portion closest to the outflow end to a portion closest to theinflow end.
 14. The stent defined in claim 11, wherein the supportingstructure includes a plurality of cells arranged in rows, at least oneof the rows forming an annulus section, the plurality of first eyeletsbeing disposed adjacent the annulus section.
 15. A prosthetic heartvalve comprising: an annularly collapsible and re-expandable supportingstructure extending between an inflow end and an outflow end, thesupporting structure including a plurality of struts and a plurality ofcommissure features, the supporting structure having a progressivelyincreasing diameter from the plurality of commissure features to theoutflow end; at least one valve element selected from the groupconsisting of a leaflet, a cuff, and a buffer; and a plurality of firsteyelets disposed on the supporting structure and spaced from theplurality of commissure features, the first eyelets being disposedadjacent the inflow end, the at least one valve element being attachedto at least one first eyelet.
 16. The valve defined in claim 15, whereinthe supporting structure further comprises a plurality of vertices atthe inflow end and each of the plurality of vertices closest to theinflow end includes at least one first eyelet.
 17. The valve defined inclaim 15, further comprising a plurality of second eyelets disposed onthe supporting structure at the outflow end.
 18. The valve defined inclaim 17, wherein the supporting structure further comprises a pluralityof vertices at the outflow end, and at least one of the plurality ofvertices closest to the outflow end includes at least one second eyelet.19. The valve defined in claim 17, wherein each of the plurality ofsecond eyelets is circular.
 20. The valve defined in claim 15, whereineach of the plurality of first eyelets is circular.
 21. The valvedefined in claim 15, wherein the supporting structure includes aplurality of diamond-shaped cells arranged in rows, and the plurality offirst eyelets are disposed on selected vertices of the diamond-shapedcells.
 22. A stent for a prosthetic heart valve comprising: an annularlycollapsible and re-expandable supporting structure extending between aninflow end and an outflow end, the supporting structure including aplurality of commissure features, and having a progressively increasingdiameter from the plurality of commissure features to the outflow end;and a plurality of first eyelets disposed on the supporting structure inthe annulus section adjacent the inflow end and spaced from theplurality of commissure features.
 23. The stent defined in claim 22,wherein the annulus section tapers radially outward so as to have anincreasing diameter from a portion closest to the outflow end to aportion closest to the inflow end.
 24. The stent defined in claim 22,wherein the supporting structure includes a plurality of diamond-shapedcells arranged in rows, and the plurality of first eyelets are disposedon selected vertices of the diamond-shaped cells.
 25. The stent definedin claim 22, wherein the supporting structure further comprises aplurality of vertices at the inflow end and each of the plurality ofvertices closest to the inflow end includes at least one first eyelet.26. The stent defined in claim 22, further comprising a plurality ofsecond eyelets disposed on the supporting structure at the outflow end.27. The stent defined in claim 26, wherein the supporting structurefurther comprises a plurality of vertices at the outflow end, and atleast one of the plurality of vertices closest to the outflow endincludes at least one second eyelet.
 28. The stent defined in claim 26,wherein each of the plurality of second eyelets is circular.
 29. Thestent defined in claim 22, wherein each of the plurality of firsteyelets is circular.